EL LIMON, Panama — Original construction of the Panama Canal is thought to have flooded 29 villages, displacing 50,000 people. But the largest modernization project in the 94-year history of the waterway, officials insist, won’t force anyone to seek higher ground.

An eight-year, $5.25 billion expansion starting next year will double the canal’s capacity. Deeper, three-step locks on the Atlantic and Pacific sides will accommodate container ships, cruise liners and tankers too large for the canal’s present dimensions, planners say, while alleviating problems with traffic congestion.

But officials promise the project won’t displace anyone.

“Not a single home will be affected,” canal administrator Alberto Aleman has pledged, adding: “The project does not require any new dams, new reservoirs.”

While the area immediately beside the canal is a high-security zone where no one is allowed to live, 186,000 people have homes on islands within the canal’s wider expanses or on the banks of the surrounding basin. It’s a 1.4 million-acre area including two lakes: Gatun, off the Atlantic Ocean, and Alhajuela, created by a dam farther to the north.

Flood preventionShips are raised and lowered from the Pacific and Atlantic by a series of locks, plying the waters of Gatun Lake and the canal as they shuttle between the oceans. With each boat that passes through the locks, 55 million gallons of water is dumped out to sea.

A trio of water-saving basins will ensure the new locks reuse 60 percent of that water, replenishing the canal and helping to ensure that officials won’t need to flood communities to generate the water lost if the locks dumped into the ocean.

Aleman says the extra water needed for the expansion will raise the banks of 160-square-mile Gatun Lake by only 18 inches, and even that will only occur once a year, at the end of the rainy season.

The original site of El Limon was flooded by the digging of the canal, but now the same town is perched on a hillside, with breathtaking views of the ink-blue waters.

Panama’s environmental secretary sent representatives to towns throughout the canal zone to reassure residents. While few here seem worried enough about the canal expansion to sell their simple homes of cinderblock and concrete, some, like Jose Diaz, remain suspicious.

“No one is giving clear answers about what will happen. Why? Because they aren’t sure,” said 38-year old Diaz, who sits on a committee that helps resolve disputes in El Limon. “The government is thinking about making money, not all the implications.”

Will cemetery be casualty?Feliciano Medina, a 57-year-old member of the town council, gazed from El Limon’s cemetery to the lake, about 25 yards below. “Look where the water is and where the cemetery is,” he said. “If the water rises some, whoa, what a mess!”

President Theodore Roosevelt arranged for Panamanian independence from Colombia in 1903 so Americans could take over a failed French effort to forge a shortcut between the seas. Throughout the life of the canal, engineers have launched major excavation projects to widen and deepen key sections. The new plan is to be the biggest expansion.

Americans first began working on a new set of locks on the Atlantic side in the 1930s, but the project was abandoned after the outbreak of World War II. The new set of locks will be constructed on the same site.

Washington controlled the waterway from its opening in 1914 until Dec. 31, 1999, when it was ceded to Panama, which considers the waterway a crucial resource.

“If I have to move, I’ll move,” said Andres Luna, a 68-year-old retiree who built tugboats for the canal for 31 years, but has long since retired to a home in El Limon on Lake Gatun’s banks. “This is Panama and the canal gets what it needs. The good of the country is more important than some houses.”